\startbuffer[DemoPage]
    \hfill
    \vfill    
    \midaligned{\bold{\pagenumber}}
    \vfill
    \hfill
\stopbuffer


\setupbodyfont[ss,60pt]
\setuplayout [margin=0pt, width=fit]
\setuppagenumbering [alternative=doublesided,location=]
\showframe
\setuplayout [location=middle,marking=on]


\setuppapersize[A7][A3,landscape] 
\setuparranging [2*8]

\starttext
    \dorecurse{16}{\getbuffer[DemoPage]\page}
\stoptext


% \def\Schema{2*4}

% \setuppapersize[A9,landscape][A7,landscape] 

% % the schema being tested
% \setuparranging [\Schema] 

% % Visuals
% \setupbodyfont[ss,10pt]

% \setuplayout [margin=0pt, width=fit, header=2.8ex, footer=2.8ex]
% \setupalign[middle,hilo]
% \setuppagenumbering [alternative=doublesided,location=footer]
% \setupheadertexts[\CONTEXT\ imposition test]

% \showframe
% \setupbackgrounds [text][text][background=color,backgroundcolor=lightgray] 

% % Where the block of pages is placed on the sheet 
% % (relevant if there is space left over.)
% \setuplayout [location=middle,marking=on]

% \startbuffer[Fakepage]
%     \strut
%     \blank
%     \bold{[\Schema]}
%     \vfill
%     This is page \recurselevel
%     \vfill
% \stopbuffer

% \starttext
%     \dorecurse{16}{\getbuffer[Fakepage]\page}
% \stoptext